/*
 * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.core.el.juel.tree.impl.ast;

import jakarta.el.ELContext;
import jakarta.el.ELException;
import org.activiti.core.el.juel.misc.BooleanOperations;
import org.activiti.core.el.juel.misc.NumberOperations;
import org.activiti.core.el.juel.misc.TypeConverter;
import org.activiti.core.el.juel.tree.Bindings;

public class AstUnary extends AstRightValue {

    public interface Operator {
        public Object eval(Bindings bindings, ELContext context, AstNode node);
    }

    public abstract static class SimpleOperator implements Operator {

        public Object eval(Bindings bindings, ELContext context, AstNode node) {
            return apply(bindings, node.eval(bindings, context));
        }

        protected abstract Object apply(TypeConverter converter, Object o);
    }

    public static final Operator EMPTY = new SimpleOperator() {
        @Override
        public Object apply(TypeConverter converter, Object o) {
            return BooleanOperations.empty(converter, o);
        }

        @Override
        public String toString() {
            return "empty";
        }
    };
    public static final Operator NEG = new SimpleOperator() {
        @Override
        public Object apply(TypeConverter converter, Object o) {
            return NumberOperations.neg(converter, o);
        }

        @Override
        public String toString() {
            return "-";
        }
    };
    public static final Operator NOT = new SimpleOperator() {
        @Override
        public Object apply(TypeConverter converter, Object o) {
            return !converter.convert(o, Boolean.class);
        }

        @Override
        public String toString() {
            return "!";
        }
    };

    private final Operator operator;
    private final AstNode child;

    public AstUnary(AstNode child, Operator operator) {
        this.child = child;
        this.operator = operator;
    }

    public Operator getOperator() {
        return operator;
    }

    @Override
    public Object eval(Bindings bindings, ELContext context) throws ELException {
        return operator.eval(bindings, context, child);
    }

    @Override
    public String toString() {
        return "'" + operator.toString() + "'";
    }

    @Override
    public void appendStructure(StringBuilder b, Bindings bindings) {
        b.append(operator);
        b.append(' ');
        child.appendStructure(b, bindings);
    }

    public int getCardinality() {
        return 1;
    }

    public AstNode getChild(int i) {
        return i == 0 ? child : null;
    }
}
